Method for bulking tobacco



April 19, 1960 c HAMILTON ET AL 2,933,090

METHOD FOR BULKING TOBACCO Filed March 15, 1956 5 Sheets-Sheet lINVENTORS'. CHARLES M. HAMILTON EDWIN W- HINEJI. GEORGE D-FLAITH ATTY-S.

April 19, 1960 c; LToN ETAL 2,933,090

METHOD FOR BULKING TOBACCO 3 Sheets-Sheet 2 Filed March 15, 1956mvsmons: CHARLES M. HAMILTON EDWIN w. HINE,H. GEORGE o. FLAITH ATTYS.

April 19, 196 c. M. HAMILTON ETAL 2,933,090

METHOD FOR BULKING TOBACCO 3 Sheets-Sheet 3 Filed March 15. 1956 m w nEH GO TT I mA wWHL mA H D SWC EDR LEO R E A G H C M OE ATTYS,

United States Patent METHOD FOR BULKING TOBACCO Charles M. Hamilton,'Glenside, and Edwin W. Hine II and George D. Flaith, Philadelphia, Pa.,assignors to Proctor & Schwartz, Inc., Philadelphia, Pa., a corporationof Pennsylvania Application March 15, 1956, Serial No. 571,623

3 Claims. (Cl. 131-140) This invention relates to the art of bulkingtobacco, and is concerned with the provision of improvements in that artby which economies in processing steps are effected, while at the sametime providing a more effective and uniform bulking operation.

In the conventional processing of hot cut tobacco, it has been customaryto cool the tobacco after its discharge from the drying apparatus at atemperature which may be between 130 and 190 F., by tumbling it throughan [inclined screened drum while subjecting it to the cooling "effect ofa stream of air by which it was cooled to about 75-80 F. From thiscooling drum, the tobacco has been deposited on a conveyor apron bywhich it has been carried to bulking boxes, or to a bulking bin througha redresser, which served, to fluff the tobacco, and to render itsubstantially uniform throughout its mass, both in moisture content andin general consistency.

An object of the present invention has been to provide a process inwhich the cooling, as a. separate step, may be eliminated, and performedin conjunction with the bulking operation in a manner which not onlyeliminates the separate cooling, but actually improves the effectivenessof the bulking.

A further object has been to combine the cooling and bulking functionsin a manner which not only eliminates the separate cooling as discussedabove, but also reduces the time required for effective bulking, therebyproviding greater throughput and corresponding economy in use of thebulking apparatus.

A further object has been to combine with the bulking operation acooling feature by which the effectiveness of the bulking operation isimproved to provide a superior and more uniform product.

In the attainment of these objects, the hot tobacco is passed directlyfrom the drying step into a bulking chamber in which it is advanced on aforaminous conveyor, while being subjected to the gentle agitating andmoisture redistributing effect of streams of conditioned air passedvertically through the conveyor and tobacco at a rate sufficient toprovide the desired cooling and prevent undesirable rise of chambertemperature due to continued introduction of tobacco, but insufiicientto remove any substantial amount of moisture from the body of tobaccobeyond that normally lost during cooling, or to disturb the deposit oftobacco beyond the mild agitating effect. While there is someevaporation of moisture from parts of the bed of tobacco, this is forthe most part redeposited in other parts of the bed. The net effect istherefore to obtain more rapidly the desired redistribution of moisturecontent and the rendering of the bed of tobacco more uniformlyconsistent.

Still further objects and advantages of the invention, and the manner inwhich they have been attained, will be evident from reading of thefollowing detailed description in the light of the attached drawing, inwhich:

Figure 1A is a side elevation, partly broken away,

-illustrating the left end of the apparatus in practice of *the processof the invention,

2,933,090 Patented Apr. 19, 1960 Figure 1B is a side elevation of theright end of the apparatus,

Figures 2A and 2B are plan views corresponding respectively to Figures1A and 1B,

Figures 3 and 4 are cross-sections taken on the lines 3-3 and 4-4,respectively, of Figure 1A.

The preferred apparatus for use in practice of the invention includes ahousing 10 which encloses a chamber through which the CILllZ tobaccopasses to provide the bulking operation. As illustrated, the hot tobaccois deposited immediately after its discharge from the drier, from anoverhead conveyor which distributes it laterally across foraminousconveyor 11, upon the upper or conveying run of conveyor 11. Conveyor111 is continuously driven to advance the tobacco longitudinally of thehousing during continuous deposit of tobacco from the dryer, and therate of advance of conveyor 11 is relatively slow, being correlated withthe rate of continuous receipt of the tobacco from the dryer so as tomaintain a constantly advancing bed of tobacco of substantial thickness,say 3-6, upon conveyor 11.

Conveyor 11 may be driven by motor 12 through a system of pulleys bybelt 13, and this belt may also be interconnected with underlyingconveyors 14 and 15, so that they are driven simultaneously withconveyor 11, conveyor 15 being driven in the same direction and conveyor14 in the opposite direction. As the tobacco advances continuously fromthe receiving end 16 (Figure !].A) at which it is supplied to conveyor11 by overhead conveyor 17 to the discharge end 18 (Figure 1B) fromwhich it is discharged upon conveyor 14, a body of cooling andconditioning air is constantly passed through the tobacco. This coolingair may, for example, be drawn into housing 10 from the air conditionedroom or space surrounding it, through inlet ports or openings 19 in theside wall of the housing.

The circulating system provided to create the gentle flow of cooling airfor mildly agitating the tobacco to assist in the bulking while at thesame time providing the desired cooling and moisture redistribution mayinclude a blower 22 driven by a motor 23 to suck air into the housingthrough inlet ports 19. and discharge it through outlet 24. In passingfrom inlets 19 to outlet 24, the air is drawn upwardly throughout thelength and width of the advancing bed of tobacco from inlets 19 intospaced overlying hoods 25 and thence into a common exhaust duct 26 whichis interconnected at its discharge end with the housing 27 of blower 22.It will thus be seen that air is sucked continuously upwardly andvertically through the bed of tobacco as it advances on conveyor 11.This air may be continuously recirculated instead of being dischargedinto the surrounding room by interconnecting the exhaust of fan orblower 22 directly to ports 19 and including suitable cooling and otherair conditioning units within the duct-work system by which the air iscontinuously recirculated.

Sealing members in the form of hinged, counterweighted bafiie plates 28are provided at the receiving and discharge ends of the housing inpositions overlying the conveying run of conveyor 11, as illustrated inFigures 1A and 1B. As illustrated in broken and full lines respectivelyin Figure 1A, the seals 28 are pressed upwardly by the advancing bed oftobacco and maintained in sealing contact therewith by the force ofgravity, and the longitudinally extending bed of tobacco on conveyor 11,as confined between the conveyor and the seals 28, serves to prevent, orat least minimize, undesired flow of air longitudinally of the bed oftobacco beyond the location of the seals. By reference to Figure 3, itwill be seen that the tobacco is confined between seals 28 and verti- InFigure 1B, thesealing member 28 is shown in conveyor 15 in thesefigures. In addition to the sealing plates 28 and 29., there arepreferably provided sealing :strips 32 between the upper and lower runsof the respective conveyors 1 1, 14 and 15 adjacent the ends thereof,.asillust-rated in Figures 1A and 1B. v

The bed of tobacco, which has been cooled at least partially down to theultimately desired temperature during the process of conveying it fromthe receiving to the discharging ends of conveyor 11, is directed byguide plate or bafiie 33 from the'discharge end of conveyor 11 .to theunderlying receiving end of conveyor .14, and is next passed asillustrated by the arrow in Figures 1B and 1A',.-to the end of conveyorldvadiacent the receiviug'end -of conveyor 11. This tobacco may then bedischarged from conveyor 14 and directed by guide plate or bafile .34onto the upper side of conveyor 15, whence it is passed to the dischargeend of that conveyor as illustrated in .Figure 1B, and discharged ontoan underlying transversely extending conveyor 35 by which it isdischarged fromthe housing 10.

In addition to the inlet ports or openings 19 by which air is suckedthrough the bed of tobacco upon conveyor 11,-there may also be providedcorresponding inlet ports or openings 36 through which cooling andconditioning air is similarly sucked into the housing and upwardlythrough the bed of tobacco advancing upon conveyor 15.

A plurality of spaced, vertically extending ductsorcon- .duits 37 arealso provided with their inlets communicating with the space between theconveyor run of conveyor 14 and its underlying return run, and theseducts 37 are interconnected with the main exhaust duct 26 as indicatedat 38 (Figure 3), so that theblower .22 serves not only to draw atupwardly through hoods 25, but also through these ducts'37 into theexhaust duct 26.

The results of the provision of this combination .of inlet ports andducts are illustrated in Figures 3 and 4. As noted above in discussionof the cooling and bulking function as performed on conveyor 11, and asillustrated in "Figure 4, a partfiof the stream of air sucked into thehousing through inlet port 19 passes upwardly through hoods25 into theexhaust .duct 26. At the same time,

a part of this air passes downwardly and longitudinally, as illustratedby the arrows in Figures 3 and 4, from the inlet ports 19 through thebed of tobacco upon conveyor 14, and into the laterally inwardly bentextensions 39 of ducts 37. Air entering'the housing through inlet ports.36 is also sucked through the bed of tobacco in a vertical direction,being drawn from these inlets into exten- ,sion 39 of ducts 37, asillustrated by the upwardly directed "arrows toward the bottom ofFigures 3 and 4. Air for cooling and mildly agitating the tobacco isthus directed downwardly through the bed of tobacco upon conveyor 14,and upwardly through the bed of tobacco on conveyor. 15, at the sametime that air isbeing directedup- WaIdly-through conveyor 11 and itsoverlying bed of tobacco, so that the cooling and conditioning andagitating action is continuous, substantially from end to end, of theadvancing beds of tobacco on the three upper conveyingruns of conveyors11, 14 and 15, as this tobacco moves tortuously through the apparatus.

When the invention is practiced by passage of cooling and conditioningand agitating air through the bed of tobacco as it advances-continuouslyon each of conveyors I 11, '14 and '15, .as illustrated, the conveyors14 and "15 will be :driven-atapproxirnately the same speed as con-=veyor 11, so'that-tobacco'willbe maintainediin substan- I Etiallyuniform depth on all three of theseccnveyors durits passage through :theapparatus and treatment by theprocess of the invention. The apparatusmay thus be continuously used, hour after hour, in the continuingtreatment of tobacco supplied continuously into the receiving end 16 anddischarged from the housing 10 upon conveyor 35.

While the invention has'been described above primarily in relation to aprocess in which the cooling and conditioning and agitating functionsare performed during the entire course .of progression of the tobaccoupon the successive conveyors of the bulking chamber, it is of coursepossible to adopt various modifications. As one example of suchmodification, the cooling and agitating may be performed only upon thetobacco as it progresses along the uppermost conveyor 11, and the lowerconveyors 14 and 15 may be employed merely to provide the addi tionaltime factor required for most effective bulking. In

such a process or arrangement, the bed of tobacco upon the underlyingconveyors 14 and 15 may be allowed .to accumulate in substantiallygreater depth than that upon conveyor 11. For example, the tobacco uponuppermost conveyor 11, through which the :air is sucked continuouslyupwardly, may be approximately 6 inches in thicknesaand the tobacco onthe lower conveyors 14 and 15 maybe allowedto accumulate to a depth of24 inches,

by running these conveyors at a much slower speed than the conveyor 11.Of course, if conveyors 14 and 15 are not ,to'be used to assist in theagitating function, the

lowermost inlet ports 36 will beclosed off or eliminated,

as will also the vertical ducts 37.

Example 1 bnlking u'nit provided for cut tobacco substantially asillustrated in the drawing. This unit is3 conveyors ,high, and supplies1'0 cigarette-making machines. It is 78 conveyor.

The conveyors are operated at a surface speed of approximately 12 inchesper minute. The cut tobacco is, therefore, exposed to gentle agitationand'air passage through the bed of tobacco for approximately .3

hours. At the end of this time, the moisture content and temperature ofthe tobacco is substantially uniform throughout the bulk and the tobaccois ready for use.

In addition, a complete redistribution of tobacco on the conveyorsoccurs at the end of the run of the top and the middle conveyors whichfurther enhances the opening and uniformity of the final product.

Example 2 A bulking unit of the same size as in Example 1, that is 78feet overall with a width of 6 feet 6 inches be- .tween side panels,supplies l0 makers as before. A static pressure difference equaljtoapproximately /s inch of water head is maintained through the topforaminous conveyor only. This pressure may be maintained by means of a10 horsepower fan. The intermediate conveyor and the bottom conveyor arenot of a foraminous apron construction, hence there is no pressuredifference apron. The tobacco is then transferred onto the intermediateconveyor and then upon the lower conveyor. The intermediate conveyor andthe bottom conveyor operate at a surface speed in the order of 3 inchesper minute. The depth of tobacco on the intermediate and bottom apronsis approximately 24 inches. No air is passed through the tobacco whileit is upon the intermediate or bottom conveyors.

Feed of tobacco to the top conveyor is discontinued after 4 hours andafter about 4% hours all three conveyors are stopped, with theintermediate and bottom conveyor aprons loaded with tobacco and with thetop apron depleted of tobacco. At this juncture the fan supplyingcooling air through the top conveyor is turned off. The tobacco is thenmaintained in a state of rest for about 3% hours so that the moisturecontent and the temperature will become uniform throughout the bulkbefore the tobacco is used in the next stage of the process. During theperiod of feed interruption, tobacco from the dryer is passed to similarbulking apparatus arranged in parallel to the first and operated instep-wise timed relation thereto.

During the period immediately prior to completion of loading of theintermediate and bottom conveyors, when the top conveyor is beingdepleted of stock, the resistance to passage of air through the topconveyor decreases, due to the fact that an increasing portion of thetop conveyor apron does not contain stock, hence the velocity of airthrough the depleted portion of the conveyor tends to increase therebycausing the tobacco to be too violently agitated. Means in the form of apervious fabric strip, having the same resistance to the flow of air asthe tobacco, can be fed into the bulker behind the depleting tobacco,thereby maintaining a uniform resistance to the flow of air. Anothermeans for achieving the same air control would be to have a series ofadjustable dampers positioned beneath the forward run of the conveyoraprons. The dampers may be actuated sequentially, closing in response toa change in velocity head, or electrically operated and closed in timedintervals.

While the invention has been disclosed primarily in relation to apreferred form of the invention, we wish it to be understood that thisinvention may be modified or refined in a number of ways withoutdeparting from its basic spirit. We therefore wish it to be understoodthat this invention is not to be limited in interpretation except by thescope of the following claims.

We claim:

1. In the cooling and bulking of tobacco, the process comprisingcontinuously depositing hot tobacco from a dryer upon a foraminousconveyor, advancing said conveyor during discharge through an enclosedcooling and bulking chamber at a rate sufliciently slow to provide acontinuously advancing bed of tobacco of substantial depth upon saidconveyor, passing cooling, conditioning and agitating air gentlyupwardly through said conveyor and said bed of tobacco in a verticaldirection as it advances slowly through said chamber, the passage of airbeing continuous and substantially throughout the length and width ofthe advancing bed, discharging said tobacco from said first conveyorupon a second conveyor advancing at a slower rate than said firstconveyor in the opposite direction and thereby providing a continuouslyadvancing bed of tobacco of greater depth upon said second conveyor andmaintaining tobacco on said second conveyor quiescent by avoidingpassage of air therethrough to complete said bulking thereof.

2. A process as claimed in claim 1 and further including discontinuingdeposit of tobacco on said first conveyor and thereafter, afterdischarging the tobacco from the first conveyor onto said secondconveyor stopping both conveyors with the second conveyor loaded withtobacco and the first conveyor depleted of tobacco, and maintaining thetobacco on said second conveyor in a state of rest for a substantialperiod of time to bring moisture content and temperature uniformthroughout the bulk of tobacco.

3. A process as claimed in claim 2, and maintaining resistance to flowof air through said first conveyor uniform through the depleted portionof said first conveyor as tobacco is discharged therefrom to prevent tooviolent agitation of the tobacco.

References Cited in the file of this patent UNITED STATES PATENTS838,361 Schwartz Dec. 11, 1906 1,017,951 Brown Feb. 20, 1912 2,067,115Bogaty Jan. 5, 1937 2,179,644 Rundell Nov. 14, 1939 2,732,844 Stark Jan.31, 1956 2,777,446 Bogaty Jan. 15, 1957 FOREIGN PATENTS 10,802 GreatBritain 1897 440,482 Great Britain Dec. 27, 1935 534,613 Germany Sept.29, 1931 544,862 Germany Feb. 24, 1932 596,553 Great Britain Jan. 6,1948

